43 research outputs found
Microbial diversity of soils of the Sand fynbos
No full textThesis (MSc (Microbiology))--Stellenbosch University, 2008.The soil environment is thought to contain a lot of the earth’s undiscovered biodiversity. The aim of this study was to understand the extent of microbial diversity in the unique ecosystem of the Western Cape’s fynbos biome. It is known that many processes give rise to this immense microbial diversity in soil. In addition the aim
was to link microbial diversity with the soils physio-chemical properties as well as the
plant community’s structure. Molecular methods especially automated ribosomal intergenic spacer analysis (ARISA) was used in the study.
The most important property of environmental DNA intended for molecular ecology studies and other downstream applications is purity from humic acids and phenolic compounds. These compounds act as PCR inhibitors and need to be removed
during the DNA extraction protocol. The fist goal in the study was to develop an effective DNA extraction protocol by using cationic locculation of humic acids. The combination of cationic flocculation with CuCl2 and the addition of PVPP and KCl resulted in a high yield of DNA, suitable for PCR amplification with bacterial and fungal specific primers.
Determining the reproducibility and accuracy of ARISA and ARISA-PCR was important because these factors have an important influence on the results and effectiveness of these techniques. Primer sets for automated ribosomal intergenic
spacer analysis, ITS4/ITS5, were assessed for the characterization of the fungal communities in the fynbos soil. The primer set delivered reproducible ARISA profiles for the fungal community composition with little variation observed between ARISAPCR’s.
ARISA proved useful for the assessment and comparison of fungal diversity in ecological samples.
The soil community composition of both fungal and bacterial groups in the Sand fynbos was characterized. Soil from 4 different Sand fynbos sites was compared to investigate diversity of eubacterial and fungal groups at the local as well as a the landscape scale. A molecular approach was used for the isolation of total soil
genetic DNA. The 16S-23S intergenic spacer region from the bacterial rRNA operon was amplified when performing bacterial ARISA from total soil community DNA (BARISA).
Correspondingly, the internal transcribed spacers, ITS1, ITS2 and the 5.8S
rRNA gene from the fungal rRNA operon were amplified when undertaking fungal ARISA (F-ARISA). The community structure from different samples and sites were statistically analysed. ARISA data was used to evaluate different species
accumulation and estimation models for fungal and bacterial communities and to predict the total community richness. Diversity, evenness and dominance were the microbial communities were used to describe the extent of microbial iversity of the fynbos soils. The spatial ordination of the bacterial and fungal species richness and
diversity was considered by determining the species area relationship and beta diversity of both communities. The correlation between the soil physio-chemical properties was determined. The plant community structure data was correlated with the fungal and the bacterial community structure. The results indicated that bacterial
species numbers and diversity were continually higher at the local scale. Fungi however showed higher species turnover at the landscape scale. Bacterial community structure showed stronger links to the plant community structure whereas
the fungi community structure conformed to spatial separation patterns.
To further investigate the diversity of soil microbes the potential of genus specific
primes was investigated. The genus Penicillium is widespread in the soil environment and the extent of its diversity and distribution is however not. For this reason Penicillium was chosen as a model organism. To expand the insight into the
diversity of Penicillium species in the fynbos soil ecosystem, a rapid group specific
molecular approach would be useful. Penicillium specific primers targeting the 18S rRNA ITS gene region were evaluated. Fungal specific primers ITS4 and ITS5, targeting the internal transcribed region (ITS) were used to target Penicillium specific in the soil sample. Nested PCR, using primer Pen-10 and ITS5, was then utilized to
target Penicillium species specifically. The discrimination of Penicillium species was
possible due to length heterogeneity of this gene region. Eight different peaks was detected in the soil sample with ARISA and eight different species could be isolated on growth media. The technique proved useful for the detection and quantification of Penicillium species in the soil
Enkele Bedenkinge oor die Vervangingsprocédé as Literêre Handgreep
No full textIn this article the author voices some objections against the so called substitution procédé as method in understanding the poetry of Breytenbach. This method was devised by Cloete and followed up by Lombard in her doctoral study and in article(s).
The author is adamant that the substitution procédé is unnecessary for the understanding of Breytenbach’s poem “Klanke vir daeraad” (sounds for break of day). Furthermore; this method spurs a naive logic that actually hinders the understanding and can lead to far-fetched interpretation.
In conclusion the reader is made aware of the pitfall of “reception” and that substitution actually distorts the text
Coping in a harsh reality: The concept of the ‘enemy’ in the composition of Psalms 9 and 10
No full textIn this paper, Psalms 9 and 10 are read together from a literary, post-exilic perspective, arguing that the construct of the ‘enemy’ in this composition primarily serves to strengthen the position of the righteous. It seems that a variety of strategies are employed in this composition to establish dichotomic-ideological categories. This results in the formation of a polarity between YHWH and the enemy on the one hand and the righteous and the enemy on the other. This seems to have been a technique through which the author or authors of this composition sought to break free from their current social experience in order to create a new, just and fair reality for the righteous
Soil microbial communities associated with two commercially important plant species indigenous to the fynbos region of South Africa : cyclopia spp. (honeybush) and Aspalathus linearis (rooibos)
No full textThesis (PhD)--Stellenbosch University, 2016.ENGLISH ABSTRACT: The Cape Floristic Region (CFR) is characterized by nutrient poor soils which forged close symbiotic ties between plants and soil microorganisms for nutrient acquisition. Aspalathus linearis and Cyclopia spp. are two commercially important plant species endemic to the CFR in South Africa. These species are used to produce herbal teas known as rooibos and honeybush tea, respectively. Despite the important role soil microorganisms play in this environment, very few studies have been done to investigate the diversity and structure of the communities associated with these economically important plants. Furthermore, it is unclear what the effect of agricultural practices will be on these communities. Studies done on other agricultural systems, showed that the soil microbiome is greatly influenced by agricultural activities such as soil tillage, application of pesticides as well as monocropping systems. These activities often lead to the loss of soil productivity and biodiversity. We, therefore, hypothesised that the microbial communities associated with A. linearis and Cyclopia spp. plants will also be influenced by the respective agricultural activities. The overall aim of this study was to characterise and compare microbial communities associated with natural and commercially grown A. linearis and Cyclopia spp. plants. Furthermore, we aimed to investigated the effect different abiotic and physico-chemical factors may have on microbial communities in this unique region. Sampling was done on two occasions to include the dry, warm summer and the cold, wet winter seasons. A total of 29 bulk soil and 54 rhizosphere soil samples were collected during this study. The abiotic and physico-chemical properties of the soil samples were determined which included soil resistance, pH, total soil carbon, Na+, K+, nitrate and ammonia. Bacterial and fungal communities were characterised using next generation sequencing technology on the Ion Torrent (PGM) platform. For the bacteria, variable V4-V5 region of the 16S rRNA gene were amplified and sequenced. Fungal analysis used the internal transcribed spacer (ITS) region of the 18S rRNA gene. Bioinformatic and statistical analyses were performed using the software packages MOTHUR, PIPITS and R. No statistically significant differences were detected between bacterial communities from natural and commercial sites for both A. linearis and Cyclopia spp. plants. The plant-driven selection of rhizosphere microbiome for these two fynbos plants appeared to be very strong and was not significantly influenced by agricultural activities. However, significant differences in bacterial communities were observed between samples collected during the different seasons. These seasonal changes support the contention that microbial taxa adapt and resist environmental changes differently. Furthermore, the overall taxonomic classification indicated that all soils were dominated by the bacterial orders Acidobacteriales and Actinomycetales. Both these groups are known to be dominant soil colonizing bacteria and are able to grow under low nutrient conditions, characteristic to the fynbos region. Additionally, the most dominant fungal phyla detected in samples included the Ascomycota and Basidiomycota. Cyclopia spp. samples were mostly dominated by the orders Agaricales, Chaetothyriales and Mortierellales, whereas A. linearis samples were dominated by the orders Chaetothyriales, Eurotiales and Helotiales. The β-diversity analysis showed that the Cyclopia spp. samples tended to cluster into commercial and natural groups. This might be due to the differences measured in soil pH between these two groups. Overall, little evidence was found to support our hypothesis. Bacterial communities from natural and commercial soil of both plant species were very similar and fungal communities associated with natural and commercially grown A. linearis plants also did not reveal any significant difference. However, fungal communities associated with natural and commercially grown Cyclopia spp. plants appeared to differ. In short, this study improved our knowledge on the biodiversity of soil microorganisms associated with two commercially important fynbos plant species and elucidated on factors that affected the microbial community structures.AFRIKAANSE OPSOMMING: Die Kaap Floristiese gebied word gekenmerk deur nutriënt arme grond wat die dryfveer is vir talle simbiotiese interaksies tussen fynbos plante en grond mikrobes. Twee kommersieël belangrike fynbos plante in die Kaap Floristiese gebied sluit in Aspalathus linearis en Cyclopia spp. Hierdie plante word gebruik vir die produksie van die welbekende rooibos en heuningbos kruie tees. Ten spyte van die belangrike rol wat grond mikroörganismes in hierdie omgewing speel, is daar nog relatief min studies gedoen om die diversiteit en struktuur van die mikrobiese gemeenskappe te beskryf. Dit is verder onduidelik wat die effek van landbou praktyke op die mikrobiese gemeenskappe is. Studies wat op ander landbou sisteme gedoen is, het bewys dat die grond mikrobes sterk beïnvloed word deur aktiwiteite soos grond bewerking, toediening van plaagdoders en monokultuur. Daar is bevind dat hierdie aktiwiteite grond produktiwiteit en die diversiteit van mikrobiese gemeenskappe verlaag. Gevolglik was die hipotese van hierdie studie dat die mikrobiese gemeenskappe wat met die grond van A. linearis en Cyclopia spp. plante geassosieer word, deur landbou aktiwiteite beϊnvloed kan word. Die algehele doel van hierdie studie was om mikrobiese gemeenskappe wat geassosieër word met die grond van natuurlike en komersieël geplante A. linearis en Cyclopia spp. te beskryf en te vergelyk. Die effek wat verskillende abiotiese en fisies-chemiese faktore op hierdie gemeenskappe het, is ook ondersoek. Grondmonsters is op twee verskillende tye van die jaar versamel om beide, die droë warm somer en koue, nat winter seisoene in te sluit. ‘n Totaal van 29 omliggende en 54 wortelsfeer grond monsters is deur die loop van hierdie studie versamel. Verskillende abiotiese en fisies-chemiese faktore is bepaal en sluit in elektriese geleidings weerstand, pH, totale koolstof, Na+, K+, nitraat en ammoniak. Die samestelling van bakteriële en swam gemeenskappe is beskryf deur gebruik te maak van hoë omset volgordebepaling. Vir bakterieë is die veranderlike gebied V4-V5 van die 16S rRNA geen geamplifiseer. Swam analises het gebruik gemaak van die interne getranskribeerde spasie (ITS) gebied van die 18S rRNA geen. Bioinformatiese en statistiese analises is gedoen deur gebruik te maak van die sagteware pakkette MOTHUR, PIPITS en R. Geen statistiese beduidende verskille tussen bakteriële gemeenskappe wat geassosieer is met natuurlike en kommersieël geplante A. linearis en Cyclopia spp. is waargeneem nie. Die afleiding wat ons hieruit gemaak het is dat die plant gedrewe seleksie van die wortelsfeer grond mikrobioom vir beide plant spesies baie sterk is en dat landbou aktiwiteit geen beduidende invloed op die gemeenskappe gehad het nie. Daar is wel verskille in die bakteriële gemeenskappe tussen die seisoene waargeneem. Hierdie seisoenale verandering in mikrobiese gemeenskappe ondersteun die feit dat mikrobiese taksa verskillend reageer en aanpas by verandering in omgewingstoestande. Verder het die taksonomiese klassifikasie van die bakterieë gewys dat die ordes Acidobacteriales en Actinomycetales grond monsters gedomineer het. Hierdie twee groepe is bekend daarvoor om verskeie grond omgewings te koloniseer, veral lae nutriënt omgewings wat kenmerkend is van die fynbos gebied. Die mees dominante swam filums wat waargeneem is in al die grond monsters sluit in die Ascomycota en Basidiomycota. Die Cyclopia spp. plant grondmonsters is gedomineer deur die orders Agaricales, Chaetothyriales en Mortierellales en A. linearis plante deur die orders Chaetothyriales, Eurotiales en Helotiales. Die β-diversiteit analises van Cyclopia spp. monsters was geneig om kommersiële en natuurlike monsters saam te groepeer. Dit is heel waarskynlik as gevolg van die verskille tussen grond pH tussen hierdie twee groepe. In geheel was daar min bewyse gevind wat die hipotese van hierdie studie ondersteun. Bakteriële gemeenskappe wat geassosieer is met beide natruurlike en kommersiële grond monsters was soortgelyk vir beide plant spesies, asook swam gemeenskappe wat geassosieer is met A. linearis plante. Daar is wel verskille waargeneem in swam gemeenskappe tussen natuurlike en kommersieël geplante Cyclopia spp. Kortom, hierdie studie verbeter ons kennis rakende die biodiversiteit van mikroorganismes wat geassosieër word met twee belangrike komersiële fynbos plante. Verder brei hierdie studie meer uit oor moontlike faktore wat mikrobiese gemeenskappe in fynbos grond kan beϊnvloed.Doctora
Optimisation of automated ribosomal intergenic spacer analysis for the estimation of microbial diversity in fynbos soil
No full textAutomated ribosomal intergenic spacer analysis (ARISA) has become a commonly used molecular technique for the study of microbial populations in environmental samples. The reproducibility and accuracy of ARISA, with and without the polymerase chain reaction (PCR) are important aspects that influence the results and effectiveness of these techniques. We used the primer set ITS4/ITS5 for ARISA to assess the fungal community composition of two sites situated in the Sand Fynbos. The primer set proved to deliver reproducible ARISA profiles of the fungal community composition with little variation observed between ARISA-PCRs. Variation that occurred in a sample due to repeated DNA extraction is expected for ecological studies. This reproducibility made ARISA a useful tool for the assessment and comparison of diversity in ecological samples. In this paper, we also offered particular suggestions concerning the binning strategy for the analysis of ARISA profiles
Xhosalising English? Negotiating meaning and identity in economics
No full textThis is an Accepted Manuscript of an article published by Taylor & Francis in Southern African Linguistics and Applied Language Studies on 23 December 2010 available online: http://www.tandfonline.com/10.2989/16073614.2010.545027.As yet, very few South African studies have explored multilingual learning contexts in order to develop a better understanding of the role that students' diverse primary or hybrid languages play in meaning making in English medium universities.This paper will report on a project which set out to investigate code-switching practices in informal learning groups in the university and to distinguish the forms and functions of these code-switching practices. A particular focus has been to gain insights into the ways in which concepts transfer from one language to another in order to develop thinking on language and learning in multilingual contexts and extend theories of conceptual transfer. The particular focus of this paper is the pedagogic and social functions of this hybrid language and how its use might be tied to questions of identity. We look particularly at the way the tutor in the peer learning group used code-mixing to negotiate different identities in dealing with first a rural and then an urban group of students. We will also illustrate by means of our data ways in which English is being appropriated and Xhosalised, particularly by the urban group of students in order to negotiate meaning, identity and status on this campus and in the wider community
The soil bacterial communities of South African fynbos riparian ecosystems invaded by Australian Acacia species.
No full textRiparian ecosystem along rivers and streams are characterised by lateral and longitudinal ecological gradients and, as a result, harbour unique biodiversity. Riparian ecosystems in the fynbos of the Western Cape, South Africa, are characterised by seasonal dynamics, with summer droughts followed by high flows during winter. The unique hydrology and geomorphology of riparian ecosystems play an important role in shaping these ecosystems. The riparian vegetation in the Western Cape has, however, largely been degraded due to the invasion of non-indigenous plants, in particular Acacia mearnsii, A. saligna and A. dealbata. This study investigated the effect of hydrology and invasion on the bacterial communities associated with fynbos riparian ecosystems. Bacterial communities were characterised with automated ribosomal intergenic spacer analysis (ARISA) and 454 16S rDNA pyrosequencing. Chemical and physical properties of soil within sites were also determined and correlated with community data. Sectioning across the lateral zones revealed significant differences in community composition, and the specific bacterial taxa influenced. Results also showed that the bacterial community structure could be linked to Acacia invasion. The presence of invasive Acacia was correlated with specific bacterial phyla. However, high similarity between cleared and pristine sites suggests that the effect of Acacia on the soil bacterial community structure may not be permanent. This study demonstrates how soil bacterial communities are influenced by hydrological gradients associated with riparian ecosystems and the impact of Acacia invasion on these communities
The effect of fire scars on microbial diversity of fynbos soil
No full textThesis (MSc)--Stellenbosch University, 2017.ENGLISH ABSTRACT: Microbial communities (bacteria, archaea, fungi, protista and viruses) are essential for the maintenance of a healthy balance in soil ecosystems. There are many factors that influence and disrupt this balance, including invasive species and fire events which disturb the properties and microhabitats of soil. Riparian zones are not typically exposed to fire. However, when the riparian zones are exposed to fire, it may have significant consequences for the natural patterns and processes of a soil ecosystem and the soil microbial communities. Invasive alien woody species such as Acacia and Eucalyptus spp. have become ubiquitous across riparian environments, affecting water and nutrient cycling and reducing plant diversity. However, the approaches to clear invasive species may also have negative consequences for ecosystem functioning. The ‘slash and burn’ technique is a biomass management tool that uses the felling of invasive stands, which are then stacked to build a pile (from dead plant biomass) and burnt. This study determined the effect of burning (the ‘slash and burn’ technique) of invasive biomass (Acacia and Eucalyptus spp.) on soil bacterial and fungal diversity and community structure in fynbos riparian zones (Western Cape, South Africa).
The sites chosen for this study were within fynbos regions invaded by Acacia mearnsii (also known as black wattle) or Eucalyptus camaldulensis (river red gum). Four study sites were chosen, each at different statuses of invasion. These sites were Bainskloof, Rawsonville, Robertson and Wellington. Before the mechanical removal of invasive species, the Bainskloof and Rawsonville sites consisted predominantly of A. mearnsii, with a small percentage cover of Eucalyptus spp. at the Rawsonville site. The Robertson and Wellington sites consisted predominantly of E. camaldulensis, with a small percentage cover of Acacia spp. at the Wellington site. Changes in the microbial diversity and community structure were assessed using automated ribosomal intergenic spacer analysis (ARISA) fingerprinting. Microbial diversity profiles of ARISA were determined by means of the Shannon (H’) and Simpson’s complement (1-D) indices. Microbial community structure profile of ARISA was evaluated by means of Analysis of Similarity (ANOSIM), cluster analysis and non-metrical multidimensional scaling (NMDS). The Pearson correlation coefficient (PCC) analysis was used for the correlation between the chemical properties and microbial diversity (H’). Whereas, the principle component analysis (PCA) was used to determine which chemical properties may explain the variation of microbial community structure post-fire.
This study showed that the ‘slash and burn’ of Eucalyptus biomass had a greater impact on the soil microbial communities compared to the ‘slash and burn’ of Acacia biomass. The data indicated that the ‘slash and burn’ of Acacia biomass (Bainskloof) did not affect the bacterial diversity (H’) post-fire. In contrast, the ‘slash and burn’ of Eucalyptus biomass (Robertson and Wellington; also Rawsonville, where some Eucalyptus biomass was present in the piles) led to a steep decrease in bacterial diversity (H’) immediately post-fire which remained relatively low a year after the burn event. Furthermore, the ‘slash and burn’ of Acacia and Eucalyptus biomass had no effect on the fungal diversity (H’). This, in turn, resulted in no variation of fungal diversity (H’) within and between invasion sites throughout the study.
Post-fire, all sites demonstrated a shift in microbial community structure. In addition, all the sites showed three distinct bacterial community structures separated by different sample times. The unique microbial community structure in the Bainskloof site, a year after the burn event, could be due to the disturbance of a flood. The unique bacterial community structures in the Eucalyptus (Robertson and Wellington) and Rawsonville sites, a year after the burn event, are likely due to the successional changes of the bacterial communities after the ‘slash and burn’. Furthermore, the fungal community structures post-fire and a year after the burn event in the Eucalyptus sites could not be delineated as separate clusters. This was in contrast to the results in the Rawsonville site where the post-fire fungal community structure was different from the community structure a year after the burn event. Moreover, the fungal community structures in the Eucalyptus and Rawsonville sites a year after the burn event were similar. This similarity could possibly be due to the post-fire dominant fungal species that are beneath the soil surface layer where fire occurred or from adjacent areas around the burnt piles. These post-fire dominant fungal species have the capacity to disperse into the burnt areas by means of mycelial expansion from deeper to surface soil profiles or from the margins of the burnt piles into the burnt areas.
The sites exposed to the ‘slash and burn’ of Eucalyptus biomass showed that soil pH served as the strongest soil abiotic indicator for bacterial diversity (H’). This finding was not evident in the Bainskloof site, which was exposed to the ‘slash and burn’ of Acacia biomass. In this study, all the sites showed that the ‘slash and burn’ of Acacia and Eucalyptus biomass leads to an increase in soil pH. However, the bacterial diversity (H’) showed different trends between invasion sites post-fire. The ‘slash and burn’ of Eucalyptus biomass resulted in a decrease in bacterial diversity (H’). Whereas, the ‘slash and burn’ of Acacia biomass did not affect the bacterial diversity (H’) post-fire. As for the fungal communities, no soil abiotic properties served as a useful indicator for the fungal diversity (H’).
The soil pH, EC and PO4 concentration explained the most variation of microbial communities in the sites exposed to the ‘slash and burn’ of Eucalyptus biomass. These trends were not observed after the ‘slash and burn’ of Acacia biomass at the Bainskloof site. At this site, no variation in EC and PO4 concentration was recorded immediately post-fire. However, EC and PO4 concentration a year after the burn event was relatively higher compared to the conditions pre-fire. As for the sites exposed to the ‘slash and burn’ of Eucalyptus biomass, the soil pH, EC and PO4 concentration showed a steep increase immediately post-fire which remained relatively high a year after the burn event.
‘Slash and burn’ of Eucalyptus biomass left a patch where the fynbos vegetation did not recover. It is possible that the ‘slash and burn’ of Eucalyptus biomass may have damaged the roots and mycorrhizal fungi in the soil that consequently decreased the rate and capacity of recolonization in burnt areas. For future research, it will be useful to investigate the effect of ‘slash and burn’ of invasive biomass on specific functional groups (i.e. mycorrhizal fungi, ammonifiers and N-fixers) in the riparian zones of fynbos. It will also be of value to evaluate the recovery of these functional groups (if possible) post-fire and to determine what it means for the restoration of fynbos vegetation.
‘Slash and burn’ of Acacia biomass, however, is unclear due to the interference of a flood that occurred at the Bainskloof site during the trial period. The flood disturbed the burnt areas and led to the re-establishment of A. mearnsii. Therefore, for future research, an observational study may be considered to assess whether fynbos vegetation will recover after ‘slash and burn’ of Acacia biomass. Taken together, the results demonstrated a shift in microbial communities post-fire. However, the microbial diversity (H’) remained the similar after the ‘slash and burn’ of Acacia biomass.AFRIKAANSE OPSOMMING: Mikrobiese gemeenskappe (bakterieë, archaea, fungus, protista en virusse) is noodsaaklik vir hul funksie om ’n gesonde balans te behou in grond. Daar is baie faktore wat hierdie balans beïnvloed en ontwrig, insluitende uitheemse bome en brande wat die eienskappe en mikrohabitats van grond versteur. Rivieroewers ervaar gewoonlik nie ’n brand nie, maar indien wel kan dit moontlik ’n beduidende invloed hê op die natuurlike patrone en prosesse van die grond ekosisteem en die grondmikrobiese gemeenskappe. Uitheemse indringer bosagtige spesies soos Acacia en Eucalyptus spp. het alomteenwoordig geword in oeweromgewings, en het sodoende die water- en voedingstofsiklusse beïnvloed en het plantdiversiteit verminder. Pogings om die indringerspesies te verwyder het egter negatiewe gevolge vir die funksionering van die ekosisteem. Die ‘sny-en-brand’ tegniek word gebruik om die biomassa te beheer en bestaan uit die afkap van uitheemse bome, waarvandaar ’n ophoping van dooie plant biomassa gemaak word en daarna gebrand word. Hierdie studie fokus op die effek van vuur (die ‘sny-en-brand’ tegniek) van uitheemse bome (Acacia en Eucalyptus spp.) op die grondbakteriese en fungus diversiteit en gemeenskapstruktuur in riveroewers van fynbos (Wes-Kaap, Suid-Afrika).
Die fynbos rivieroewers wat bestudeer word in hierdie studie is bedreig deur Acacia mearnsii (black wattle) of Eucalyptus camaldulensis (river red gum). Vier studie areas was gekies, waarvan twee van die studie areas bedreig was deur A. mearnsii en E. camaldulensis, onderskeidelik. Voor die verwydering van uitheemse bome, was die Bainskloof en Rawsonville areas gedomineer deur A. mearnsii, met ’n lae persentasie van Eucalyptus spp. by die Rawsonville area. Die Robertson en Wellington areas was gedomineer deur E. camaldulensis, met ’n lae persentasie van Acacia spp. by die Wellington area. Veranderinge in die mikrobiese diversiteit en gemeenskapstruktuur was bepaal deur die geoutomatiseerde ribosomale intergeniese spasie analise (ARISA) vingerafdruk metode. Hierdie metode is gebruik om die grondmikrobiese diversiteit en gemeenskapstruktuur te analiseer. Die mikrobiese diversiteitsprofiel van ARISA was bepaal met die gebruik van die Shannon (H’) indeks en Simpson komplement (1-D) indeks. Die mikrobiese gemeenskapstruktuur profiel van ARISA is geëvalueer met behulp van die Analise van Soortgelykheid (ANOSIM), kluster analise, en die nie-metriese multidimensionele skaling (NMDS). Die Pearson-korrelasiekoëffisiënt (PCC) analise is gebruik om die korrelasie tussen die chemiese komponente en die mikrobiese diversiteit te bepaal. Die beginselkomponent-analise (PCA) is gebruik om te bepaal watter chemiese eienskappe die variasie in mikrobiese gemeenskapstruktuur na die brand veroorsaak.
Die studie bewys dat die ‘sny-en-brand’ van Eucalyptus biomassa ʼn groter impak het op die mikrobiese gemeenskappe, in vergelyking met die ‘sny-en-brand’ van Acacia biomassa. Die ‘sny-en-brand’ van Acacia biomassa (Bainskloof) het geen effek op die bakteriese diversiteit (H’ en 1-D) gehad nie. In teenstelling, het die ‘sny-en-brand’ van Eucalyptus biomassa (Robertson en Wellington; sowel as Rawsonville, wat ’n aantal Eucalyptus biomassa bevat het binne die ophopings), tot ʼn afname in bakteriese diversiteit (H’ en 1-D) gelei, wat gevolglik konstant gebly het tot ’n jaar na die brand. Met betrekking tot die fungus diversiteit (H’ en 1-D), het die ‘sny-en-brand’ van Acacia en Eucalyptus biomassa geen effek op die fungus diversiteit (H’ en 1-D) gehad nie. Die fungus diversiteit was soortgelyk tussen studie areas, voor en na die brand.
Na die ‘sny-en-brand’ van Acacia en Eucalyptus biomassa, het al die studie areas ’n verskuiwing in grondmikrobiese gemeenskapstruktuur getoon. Die bakteriese gemeenskapstruktuur, in al die studie areas, was verskillend by elke monsternemingsessie. Die oorstroming in die Bainskloof area het gelei tot ’n unieke mikrobiese gemeenskapstruktuur, ’n jaar na die brand. Die unieke bakteriese gemeenskapstrukture in die Eucalyptus en Rawsonville areas, ’n jaar na die brand, is as gevolg van die opeenvolgende veranderinge van bakteriese gemeenskappe na die brand. Die fungus gemeenskapstruktuur na die brand, in die Eucalyptus areas, was soortgelyk aan die gemeenskapstruktuur ’n jaar na die brand. In teenstelling, die fungus gemeenskapstrukture in die Rawsonville area, na die brand en ’n jaar na die brand, was verskillend. Verder, die fungus gemeenskapstrukture in die Eucalyptus en Rawsonville areas, ’n jaar na die brand was soortgelyk. Hierdie ooreenkoms kan moontlik toegeskryf word aan die dominante fungus spesies na die brand, wat voorkom onder of aan die rante van die verbrande grondoppervlakte. Hierdie dominante fungus spesies het die vermoë om oor die verbrande grondoppervlakte te versprei deur middel van miselium uitbreiding van dieper na grondoppervlak, of van die rante na binne die verbrande grondoppervlakte.
Die areas wat gebrand was met die Eucalyptus biomassa het getoon dat die grond pH as ’n sterk abiotiese indikator dien vir die grondbakteriese diversiteit (H’). Dit was nie die geval in die Bainskloof area wat deur die Acacia biomassa gebrand was nie. Al die studie areas het getoon dat die ‘sny-en-brand’ van Acacia en Eucalyptus biomassa die grond pH verhoog het, maar die neiging in bakteriese diversiteit (H’) na die brand was verskillend. Na die ‘sny-en-brand’ van Eucalyptus biomassa was daar ’n afname in bakteriese diversiteit (H’). In teenstelling, was die bakteriese diversiteit (H’) nie geaffekteer na die ‘sny-en-brand’ van Acacia biomassa nie. In hierdie studie, was daar geen korrelasie getoon tussen die abiotiese eienskappe en fungus diversiteit (H’) nie.
Die grond pH, elektriese geleidingsvermoë (EC) en fosfaat (PO4) konsentrasie verduidelik die meeste variasie tussen die mikrobiese gemeenskapstrukture na die brand, in die areas wat gebrand was met die ‘sny-en-brand’ van Eucalyptus biomassa. Hierdie tendense was nie gevind na die ‘sny-en-brand’ van Acacia biomassa (Bainskloof) nie. Na die ‘sny-en-brand’ van Acacia biomassa was daar geen variasie in EC en PO4 konsentrasie getoon nie. In teenstelling, die areas wat gebrand was met die ‘sny-en-brand’ van Eucalyptus biomassa het getoon dat daar ’n toename is in grond pH, EC en PO4 konsentrasie na die brand, wat gevolglik konstant gebly het tot ’n jaar na die brand.
Die ‘sny-en-brand’ van Eucalyptus biomassa het gelei tot brandletsels wat die plantegroei van fynbos spesies verhoed het. Dit is moontlik dat die ‘sny-en-brand’ van Eucalyptus biomassa die wortels en mikorrisa in die grond vernietig het wat gevolglik die herstel van plantegroei in gebrande areas beïnvloed het. Vir verdere navorsing sal dit nuttig wees om die effek van vuur (die ‘sny-en-brand’ tegniek) van uitheemse bome op spesifieke funksionele groepe (soos byvoorbeeld mikorrisa en N-fikseerders) in die oewersones van fynbos te bestudeer. Dit sal ook van waarde wees om die herstel van hierdie funksionele groepe (indien moontlik) na die brand te evalueer en te bepaal wat hierdie effek op die herstel van fynbosplantegroei mag hê.
Die ‘sny-en-brand’ van Acacia biomassa is onbekend as gevolg van die oorspoeling in die Bainskloof area gedurende die proefperiode. Die vloed het die verbrande oppervlakte versteur en het gelei tot die herstel van A. mearnsii. Op grond hiervan, mag dit van waarde wees om te bepaal of die fynbos plantegroei sal herstel na die ‘sny-en-brand’ van Acacia biomassa. Neem kennis dat daar ʼn verskuiwing in mikrobiese gemeenskappe getoon was en dat die mikrobiese diversiteit (H’) konstant gebly het na die ‘sny-en-brand’ van Acacia biomassa
Developing a perceived value model for the cruise experience
No full textPhD (Tourism Management), North-West University, Potchefstroom Campus, 2016The cruise industry is one of the most important economic growth sectors in the entire
tourism market and globally this industry has expanded and grown dramatically over
the past 30 years. South Africa as a cruise destination is still growing and has not yet
reached its full potential. However this study found that in recent years there has
been a decline in growth percentages, which if not addressed soon will inevitably hold
a number of complications and challenges for the industry’s future, both in South
Africa and globally. Competition levels between cruise liners are high and as a result
the market, which is mass segment orientated is becoming saturated.
Perceived value has been seen as the most important indicator for future purchase
behaviour of services, such as a cruise experience and is key to growing the cruise
market ensuring sustained growth into the future. Yet, few studies have examined
the underlying framework of perceived value for tourism activities and no studies to
date have developed a perceived value model which captures the total cruise
experience.
Therefore, the aim of this study is to develop a perceived value model for the
cruise experience.
To achieve the above mentioned, a thorough theoretical and empirical investigation
was employed. This study found a number of challenges associated with perceived
value as a field of study, some of which include: the myriad number of different
models which exist, unlimited determinants which are measured, unstandardised use
of perceived values, obscure definitions of the function of perceived value and a lack
of perceived value research in a tourism setting. These gaps are all addressed in this
study.
Grounded in perceived value theory this study explored key studies developed by
perceived value experts. After careful investigation, a number of perceived value
dimensions were recognised as well as the determining items used to measure these
values. A pilot study was conducted to measure the suitability of these items for the
cruise industry and expert advice from both academics and cruise experts was used
to amend final changes to the measuring instrument. Based on theoretical evidence it was found that the cruise tourist transitions through
various phases during the cruise experience and since it was important that the preand
post-perceptions of cruise passengers be captured, two questionnaires needed
to be developed. The South African cruise industry is seasonal (November-March)
and as it was essential that the same respondents partake in the pre- and postevaluations
of this study. Therefore, an online questionnaire was deemed the best
approach, accommodating all respondents regardless of their geographic location.
The program Adobe Form Central® (2014) was used to conduct the online survey
during the cruise season 2014/15. Nine hundred and seventy eight (978) preperceived
questionnaires were collected and on consent from the cruise passengers,
497 respondents participated in the post-perceived survey. Only those respondents
who successfully participated in both the pre- and post-perceived value
questionnaires could be used for final analysis; the remaining questionnaires were
discarded for the purpose of this study. Therefore, the number of pre- and postperceived
value questionnaires used for statistical analyses was N = 497. The sample
sizes of this research were seen as adequate to be representative of the total cruise
market during the 2014/15 South African cruise season.
In order to achieve the goal of this study, selected statistical techniques were
employed. Firstly, the validity and reliability of the questionnaire were tested and an
initial analysis (descriptive statistics) to convey the socio-demographic and cruise
traveller profile of the respondents by means of frequency tables was performed. This
was followed by two separate exploratory factor analyses employed on the pre- and
post-perceived value items, which revealed 13 reliable and valid perceived value
dimensions. These value dimensions were used as determinants of satisfaction and
loyalty in a multiple regression analysis. Other statistical analyses that were
performed included: correlations; analysis of variance (ANOVAs) and independent ttest
analysis. These analyses were used to develop the perceived value model for a
cruise experience.
The results of the study confirmed that the perceived value of a cruise experience is
in fact multifaceted. The perceived value with unique reference to a cruise experience
therefore consists of perceived epistemic value; perceived escape value; perceived
rejuvenate value; perceived emotional value; perceived novelty value; perceived
internal social value; perceived external social value, perceived social image value,
perceived recreational value, perceived service and quality value, perceived sacrifice
value, perceived package/money value and perceived risk value. Though these factors did not entirely agree with the initial classification of the value dimensions as
predicted in the literature review, they focused on appropriate and effective values to
measure the perceived value of a cruise experience. Large positive correlations were
found between both the pre- and post-perceived values indicating their
interrelatedness and dependence on one another. Various socio-demographic and
cruise traveller behaviour elements indicated large positive correlations between
various pre-perceived values and post-perceived values. Post-perceived service and
quality value was revealed as the biggest determinant of satisfaction and loyalty. The
above mentioned need to be incorporated into cruise marketing, product
development and management approaches.
This study contributes in the following ways: this study is the first of its kind as it has
not been applied to the cruise industry and more specifically to the South African
cruise industry. Added to this a perceived value model has not been developed for
the cruise experience, which measures the pre- and post-perceptions of cruise
passengers and their effect on satisfaction and loyalty. The main theoretical
contribution made by the author in this study and which can be tested by future
researchers was the development of the theoretical perceived value framework, upon
which the empirical model was based.
The methodological contributions of this study included the aspects used to develop
a perceived value model. These were not only applied for the first time in this study,
but also within a South African context. This study makes a contribution by
developing a measuring instrument which measures the pre- and post-perceived
value of a cruise experience, the cruise traveller profile and elements that are a result
of the perceived value experience (i.e. loyalty and satisfaction). Reliability and validity
for the scale were well confirmed; therefore, this measuring instrument can be
adapted and used for future studies conducted in similar settings.
Empirically this study contributed by identifying the predictors of satisfaction and
loyalty as a result of post-perceived values within a tourism context such as perceived
value and are tested for the first time. Lastly, the most significant contribution made
by this study is the development of a perceived value model, which if properly
implemented by cruise companies can increase future growth numbers and the
cruise experience can directly be improved by taking this information into account. By incorporating this model into marketing strategies for the South African cruise
market, the perceived value of a cruise experience can be predicted and controlled,
while also enhancing the cruise experience and ensuring re-visitation.Doctora
Die Waarheids- en Versoeningskommissie as Simulacrum en die rol van belydenis, vergifnis en versoening
No full textThis paper examines the relevance and validity of the� Truth and Reconciliation Commission� s Christian leitmotiv in relation to the victim hearings. It is suggested that the Commission� s emphasis on religious themes such as the search for truth, the confession of guilt, forgiveness by victims and in the final instance the promise of redemption, reconciliation and transformation may facilitate the emergence of �moral elitism� or lead to the erroneous belief that a consensus morality dictating the transformation discourse exists. In this role, it can be said that the Commission has become simulacrum for the only way through which the truth about apartheid and redemption could be found.� The religious �authority� assumed by the Commission provided the necessary legitimacy to dictate to perpetrators and victims on a very personal level. The author warns that the Commission� s religiously inspired transformation rhetoric hides ambitious political motives that try to accomplish too much, too soon
